[PATCH v2 18/18] fs/ceph/super: remove redundant field `ceph_snap_realm.parent_ino`

[Max Kellermann]

This reduces the size of the struct by another 8 bytes.

Signed-off-by: Max Kellermann <max.kellermann@xxxxxxxxx>
---
 fs/ceph/mds_client.c | 4 ++--
 fs/ceph/snap.c       | 5 ++---
 fs/ceph/super.h      | 1 -
 3 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index b4a1c126cbc9..f0b9d653ffd1 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -5044,10 +5044,10 @@ static int encode_snap_realms(struct ceph_mds_client *mdsc,
 		}
 
 		doutc(cl, " adding snap realm %llx seq %lld parent %llx\n",
-		      realm->ino, realm->seq, realm->parent_ino);
+		      realm->ino, realm->seq, realm->parent ? realm->parent->ino : 0);
 		sr_rec.ino = cpu_to_le64(realm->ino);
 		sr_rec.seq = cpu_to_le64(realm->seq);
-		sr_rec.parent = cpu_to_le64(realm->parent_ino);
+		sr_rec.parent = cpu_to_le64(realm->parent ? realm->parent->ino : 0);
 
 		err = ceph_pagelist_append(pagelist, &sr_rec, sizeof(sr_rec));
 		if (err)
diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c
index 12f80df4b651..a5f8f3f95f3b 100644
--- a/fs/ceph/snap.c
+++ b/fs/ceph/snap.c
@@ -297,7 +297,7 @@ static int adjust_snap_realm_parent(struct ceph_mds_client *mdsc,
 
 	lockdep_assert_held_write(&mdsc->snap_rwsem);
 
-	if (realm->parent_ino == parentino)
+	if (realm->parent && realm->parent->ino == parentino)
 		return 0;
 
 	parent = ceph_lookup_snap_realm(mdsc, parentino);
@@ -307,12 +307,11 @@ static int adjust_snap_realm_parent(struct ceph_mds_client *mdsc,
 			return PTR_ERR(parent);
 	}
 	doutc(cl, "%llx %p: %llx %p -> %llx %p\n", realm->ino, realm,
-	      realm->parent_ino, realm->parent, parentino, parent);
+	      realm->parent ? realm->parent->ino : 0, realm->parent, parentino, parent);
 	if (realm->parent) {
 		list_del_init(&realm->child_item);
 		ceph_put_snap_realm(mdsc, realm->parent);
 	}
-	realm->parent_ino = parentino;
 	realm->parent = parent;
 	list_add(&realm->child_item, &parent->children);
 	return 1;
diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index ca4db56ef2d0..86a5929ee5d2 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -1023,7 +1023,6 @@ struct ceph_snap_realm {
 	struct rb_node node;
 
 	u64 created, seq;
-	u64 parent_ino;
 	u64 parent_since;   /* snapid when our current parent became so */
 
 	u64 *prior_parent_snaps;      /* snaps inherited from any parents we had prior to parent_since */
-- 
2.47.3